1. Field
The invention is in the field of gas sampling probes for industrial furnaces.
2. State of the Art
A variety of gas sampling probes for industrial furnaces have been developed in the past utilizing a fluid coolant for cooling purposes. However, there has been left considerable room for improvement from the standoints of effective operation and simplicity of construction. A structurally simple probe utilizing open-ended, concentric tubes is shown in Thoen U.S. Pat. No. 3,559,491 issued Feb. 2, 1971; the inner sampling tube or tubes are, however, made of a porous ceramic material, which results in a very expensive probe. Furthermore, it is sensitive to thermal changes and cannot be cooled. Moreover, such tubes must be flushed out periodically to remove accumulated particulate matter, so they won't become plugged.
3. Objectives
Principal objectives in the making of the present invention were to utilize an applied coolant fluid such as steam or water vapor as others had done, but with the structural simplicity of concentric tubes of a corrosion and heat resistant material such as stainless steel, with venting at the tip of the probe, and with a continuous cleaning action utilizing the coolant fluid as a cleaning agent.